The structure of vinylic halide is
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 1-bromocyclohex-1-ene
Halogen compounds are classified by the kind of carbon atom that carries the halogen:
Alkyl halide: X on an sp3 carbon of an alkyl group, as in \( \ce{C2H5Br} \).
Allylic halide: X on an sp3 carbon next to a C=C double bond, as in \( \ce{CH2=CH-CH2Br} \).
Vinylic halide: X on an sp2 carbon of the C=C double bond itself, as in \( \ce{CH2=CH-Br} \).
Aryl halide: X directly on an sp2 carbon of an aromatic ring, as in \( \ce{C6H5Br} \).
In the structure of Option (2), 1-bromocyclohex-1-ene, the bromine atom sits on one of the two carbon atoms of the ring double bond. That carbon is sp2 hybridised and part of C=C, so this compound is the vinylic halide.
Why the other options are incorrect
Option (1) \(C_2H_5X\) — Incorrect. Ethyl halide has X on an sp3 carbon with no double bond; it is a primary alkyl halide.
Option (3) bromobenzene — Incorrect. Here Br is bonded to an sp2 carbon of a benzene ring, so it is an aryl halide.
Option (4) 4-chlorocyclohex-1-ene — Incorrect. Here Cl is on an sp3 ring carbon that is not next to the double bond (two carbons away from it), so it is neither vinylic nor allylic; it is a secondary alkyl halide.
NCERT (2026-27 edition):
Vinylic Halides
